A vehicle may be equipped with a power supply control apparatus that controls power supply from a battery to a load (see JP 5408352B, for example). The power supply control apparatus disclosed in Patent Document 1 includes an N-channel FET (Field Effect Transistor) that functions as a semiconductor switch, and this FET is provided in a current path from a positive electrode of a battery to one end of a load. By switching this FET on or off, power supply through the current path is controlled. The positive electrode of the battery and the one end of the load are respectively connected to the drain and source of the FET, whereas the negative electrode of the battery and the other end of the load are grounded.
The power supply control apparatus disclosed in JP 5408352B further includes a charging circuit that charges a capacitor, a so-called input capacitance, provided between the drain and gate of the FET. When the FET is switched on, the charging circuit charges this capacitor by supplying current to the capacitor from the gate side. As a result, a voltage at the gate becomes higher than or equal to a predetermined voltage, and thus the FET is switched on. For charging the capacitor, the charging circuit outputs, to the gate of the FET, a voltage higher than an input voltage that is input from the battery to the drain of the FET, and charges the capacitor.